Do both anaerobic digestion and composting generate air pollutants?
The composting process releases large amounts of ammonia and volatile organic compounds (VOCs), and oftentimes odors. Moreover, to some extent composting inadvertently generates methane. Since as a practical matter the methane cannot be captured for use, it is emitted as a greenhouse gas. In California, emissions from composting facilities are now strictly regulated and require significant effort for compliance. In contrast, anaerobic digestion occurs in sealed tanks, resulting in the capture of methane and the sparing of fossil fuel and emissions to the atmosphere.
